/*  _______         ____    __         ___    ___
 * \    _  \       \    /  \  /       \   \  /   /       '   '  '
 *  |  | \  \       |  |    ||         |   \/   |         .      .
 *  |  |  |  |      |  |    ||         ||\  /|  |
 *  |  |  |  |      |  |    ||         || \/ |  |         '  '  '
 *  |  |  |  |      |  |    ||         ||    |  |         .      .
 *  |  |_/  /        \  \__//          ||    |  |
 * /_______/ynamic    \____/niversal  /__\  /____\usic   /|  .  . ibliotheque
 *                                                      /  \
 *                                                     / .  \
 * readstm.c - Code to read a ScreamTracker 2         / / \  \
 *             module from an open file.             | <  /   \_
 *                                                   |  \/ /\   /
 * By Christopher Snowhill.                           \_  /  > /
 *                                                      | \ / /
 *                                                      |  ' /
 *                                                       \__/
 */

// IT_STEREO... :o
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#include "dumb.h"
#include "internal/it.h"

#ifdef _MSC_VER
#define strnicmp _strnicmp
#else
#if defined(unix) || defined(__unix__) || defined(__unix)
#include <strings.h>
#endif
#define strnicmp strncasecmp
#endif

static int it_stm_read_sample_header(IT_SAMPLE *sample, DUMBFILE *f,
                                     unsigned short *offset) {
    dumbfile_getnc((char *)sample->filename, 12, f);
    sample->filename[12] = 0;

    memcpy(sample->name, sample->filename, 13);

    dumbfile_skip(f, 2);

    *offset = dumbfile_igetw(f);

    sample->length = dumbfile_igetw(f);
    sample->loop_start = dumbfile_igetw(f);
    sample->loop_end = dumbfile_igetw(f);

    sample->default_volume = dumbfile_getc(f);

    dumbfile_skip(f, 1);

    sample->C5_speed = dumbfile_igetw(f) << 3;

    dumbfile_skip(f, 6);

    if (sample->length < 4 || !sample->default_volume) {
        /* Looks like no-existy. */
        sample->flags &= ~IT_SAMPLE_EXISTS;
        sample->length = 0;
        *offset = 0;
        return dumbfile_error(f);
    }

    sample->flags = IT_SAMPLE_EXISTS;
    sample->global_volume = 64;
    sample->default_pan = 0; // 0 = don't use, or 160 = centre?

    if ((sample->loop_start < sample->length) &&
        (sample->loop_end > sample->loop_start) &&
        (sample->loop_end != 0xFFFF)) {
        sample->flags |= IT_SAMPLE_LOOP;
        if (sample->loop_end > sample->length)
            sample->loop_end = sample->length;
    }

    // Do we need to set all these?
    sample->vibrato_speed = 0;
    sample->vibrato_depth = 0;
    sample->vibrato_rate = 0;
    sample->vibrato_waveform = IT_VIBRATO_SINE;
    sample->finetune = 0;
    sample->max_resampling_quality = -1;

    return dumbfile_error(f);
}

static int it_stm_read_sample_data(IT_SAMPLE *sample, DUMBFILE *f) {
    if (!sample->length)
        return 0;

    sample->data = malloc(sample->length);
    if (!sample->data)
        return -1;

    dumbfile_getnc(sample->data, sample->length, f);

    return dumbfile_error(f);
}

static int it_stm_read_pattern(IT_PATTERN *pattern, DUMBFILE *f,
                               unsigned char *buffer) {
    int pos;
    int channel;
    int row;
    IT_ENTRY *entry;

    pattern->n_rows = 64;

    if (dumbfile_getnc((char *)buffer, 64 * 4 * 4, f) != 64 * 4 * 4)
        return -1;

    pattern->n_entries = 64;
    pos = 0;
    for (row = 0; row < 64; ++row) {
        for (channel = 0; channel < 4; ++channel) {
            if (buffer[pos + 0] | buffer[pos + 1] | buffer[pos + 2] |
                buffer[pos + 3])
                ++pattern->n_entries;
            pos += 4;
        }
    }

    pattern->entry = malloc(pattern->n_entries * sizeof(*pattern->entry));
    if (!pattern->entry)
        return -1;

    entry = pattern->entry;
    pos = 0;
    for (row = 0; row < 64; ++row) {
        for (channel = 0; channel < 4; ++channel) {
            if (buffer[pos + 0] | buffer[pos + 1] | buffer[pos + 2] |
                buffer[pos + 3]) {
                unsigned note;
                note = buffer[pos + 0];
                entry->channel = channel;
                entry->mask = 0;
                entry->instrument = buffer[pos + 1] >> 3;
                entry->volpan =
                    (buffer[pos + 1] & 0x07) + (buffer[pos + 2] >> 1);
                entry->effect = buffer[pos + 2] & 0x0F;
                entry->effectvalue = buffer[pos + 3];
                if (entry->instrument && entry->instrument < 32)
                    entry->mask |= IT_ENTRY_INSTRUMENT;
                if (note < 251) {
                    entry->mask |= IT_ENTRY_NOTE;
                    entry->note = (note >> 4) * 12 + (note & 0x0F);
                }
                if (entry->volpan <= 64)
                    entry->mask |= IT_ENTRY_VOLPAN;
                entry->mask |= IT_ENTRY_EFFECT;
                switch (entry->effect) {
                case IT_SET_SPEED:
                    /* taken care of in the renderer */
                    break;

                case IT_BREAK_TO_ROW:
                    entry->effectvalue -= (entry->effectvalue >> 4) * 6;
                    break;

                case IT_JUMP_TO_ORDER:
                case IT_VOLUME_SLIDE:
                case IT_PORTAMENTO_DOWN:
                case IT_PORTAMENTO_UP:
                case IT_TONE_PORTAMENTO:
                case IT_VIBRATO:
                case IT_TREMOR:
                case IT_ARPEGGIO:
                case IT_VOLSLIDE_VIBRATO:
                case IT_VOLSLIDE_TONEPORTA:
                    break;

                default:
                    entry->mask &= ~IT_ENTRY_EFFECT;
                    break;
                }
                if (entry->mask)
                    ++entry;
            }
            pos += 4;
        }
        IT_SET_END_ROW(entry);
        ++entry;
    }

    pattern->n_entries = (int)(entry - pattern->entry);

    return 0;
}

static DUMB_IT_SIGDATA *it_stm_load_sigdata(DUMBFILE *f, int *version) {
    DUMB_IT_SIGDATA *sigdata;

    char tracker_name[8];

    unsigned short sample_offset[31];

    int n;

    sigdata = malloc(sizeof(*sigdata));
    if (!sigdata)
        return NULL;

    /* Skip song name. */
    dumbfile_getnc((char *)sigdata->name, 20, f);
    sigdata->name[20] = 0;

    dumbfile_getnc(tracker_name, 8, f);
    n = dumbfile_getc(f);
    if (n != 0x02 && n != 0x1A && n != 0x1B) {
        free(sigdata);
        return NULL;
    }
    if (dumbfile_getc(f) != 2) /* only support modules */
    {
        free(sigdata);
        return NULL;
    }
    if (strnicmp(tracker_name, "!Scream!", 8) &&
        strnicmp(tracker_name, "BMOD2STM", 8) &&
        strnicmp(tracker_name, "WUZAMOD!", 8)) {
        free(sigdata);
        return NULL;
    }

    *version = dumbfile_mgetw(f);

    sigdata->song_message = NULL;
    sigdata->order = NULL;
    sigdata->instrument = NULL;
    sigdata->sample = NULL;
    sigdata->pattern = NULL;
    sigdata->midi = NULL;
    sigdata->checkpoint = NULL;

    sigdata->n_instruments = 0;
    sigdata->n_samples = 31;
    sigdata->n_pchannels = 4;

    sigdata->tempo = 125;
    sigdata->mixing_volume = 48;
    sigdata->pan_separation = 128;

    /** WARNING: which ones? */
    sigdata->flags = IT_OLD_EFFECTS | IT_COMPATIBLE_GXX | IT_WAS_AN_S3M |
                     IT_WAS_AN_STM | IT_STEREO;

    n = dumbfile_getc(f);
    if (n < 32)
        n = 32;
    sigdata->speed = n;
    sigdata->n_patterns = dumbfile_getc(f);
    sigdata->global_volume = dumbfile_getc(f) << 1;
    if (sigdata->global_volume > 128)
        sigdata->global_volume = 128;

    dumbfile_skip(f, 13);

    if (dumbfile_error(f) || sigdata->n_patterns < 1 ||
        sigdata->n_patterns > 99) {
        _dumb_it_unload_sigdata(sigdata);
        return NULL;
    }

    sigdata->sample = malloc(sigdata->n_samples * sizeof(*sigdata->sample));
    if (!sigdata->sample) {
        _dumb_it_unload_sigdata(sigdata);
        return NULL;
    }
    for (n = 0; n < sigdata->n_samples; n++)
        sigdata->sample[n].data = NULL;

    if (sigdata->n_patterns) {
        sigdata->pattern =
            malloc(sigdata->n_patterns * sizeof(*sigdata->pattern));
        if (!sigdata->pattern) {
            _dumb_it_unload_sigdata(sigdata);
            return NULL;
        }
        for (n = 0; n < sigdata->n_patterns; n++)
            sigdata->pattern[n].entry = NULL;
    }

    memset(sigdata->channel_volume, 64, 4);
    n = 32 * dumb_it_default_panning_separation / 100;
    sigdata->channel_pan[0] = 32 + n;
    sigdata->channel_pan[1] = 32 - n;
    sigdata->channel_pan[2] = 32 + n;
    sigdata->channel_pan[3] = 32 - n;

    for (n = 0; n < sigdata->n_samples; ++n) {
        if (it_stm_read_sample_header(&sigdata->sample[n], f,
                                      &sample_offset[n])) {
            _dumb_it_unload_sigdata(sigdata);
            return NULL;
        }
    }

    sigdata->order = malloc(128);
    if (!sigdata->order) {
        _dumb_it_unload_sigdata(sigdata);
        return NULL;
    }

    /* Orders, byte each, length = sigdata->n_orders (should be even) */
    dumbfile_getnc((char *)sigdata->order, *version >= 0x200 ? 128 : 64, f);
    if (*version < 0x200)
        memset(sigdata->order + 64, 0xFF, 64);
    sigdata->restart_position = 0;

    for (n = 127; n >= 0; --n) {
        if (sigdata->order[n] < sigdata->n_patterns)
            break;
    }
    if (n < 0) {
        _dumb_it_unload_sigdata(sigdata);
        return NULL;
    }
    sigdata->n_orders = n + 1;

    for (n = 0; n < 128; ++n) {
        if (sigdata->order[n] >= 99)
            sigdata->order[n] = 0xFF;
    }

    if (sigdata->n_patterns) {
        unsigned char *buffer = malloc(64 * 4 * 4);
        if (!buffer) {
            _dumb_it_unload_sigdata(sigdata);
            return NULL;
        }
        for (n = 0; n < sigdata->n_patterns; ++n) {
            if (it_stm_read_pattern(&sigdata->pattern[n], f, buffer)) {
                free(buffer);
                _dumb_it_unload_sigdata(sigdata);
                return NULL;
            }
        }
        free(buffer);
    }

    for (n = 0; n < sigdata->n_samples; ++n) {
        if (sample_offset[n]) {
            if (dumbfile_seek(f, sample_offset[n] * 16, DFS_SEEK_SET) ||
                it_stm_read_sample_data(&sigdata->sample[n], f)) {
                _dumb_it_unload_sigdata(sigdata);
                return NULL;
            }
        } else {
            sigdata->sample[n].flags = 0;
            sigdata->sample[n].length = 0;
        }
    }

    if (_dumb_it_fix_invalid_orders(sigdata) < 0) {
        _dumb_it_unload_sigdata(sigdata);
        return NULL;
    }

    return sigdata;
}

DUH *dumb_read_stm_quick(DUMBFILE *f) {
    sigdata_t *sigdata;
    int ver;

    DUH_SIGTYPE_DESC *descptr = &_dumb_sigtype_it;

    sigdata = it_stm_load_sigdata(f, &ver);

    if (!sigdata)
        return NULL;

    {
        char version[16];
        const char *tag[2][2];
        tag[0][0] = "TITLE";
        tag[0][1] = (const char *)(((DUMB_IT_SIGDATA *)sigdata)->name);
        tag[1][0] = "FORMAT";
        version[0] = 'S';
        version[1] = 'T';
        version[2] = 'M';
        version[3] = ' ';
        version[4] = 'v';
        version[5] = '0' + ((ver >> 8) & 15);
        version[6] = '.';
        if ((ver & 255) > 99) {
            version[7] = '0' + ((ver & 255) / 100);
            version[8] = '0' + (((ver & 255) / 10) % 10);
            version[9] = '0' + ((ver & 255) % 10);
            version[10] = 0;
        } else {
            version[7] = '0' + ((ver & 255) / 10);
            version[8] = '0' + ((ver & 255) % 10);
            version[9] = 0;
        }
        tag[1][1] = (const char *)&version;
        return make_duh(-1, 2, (const char *const(*)[2])tag, 1, &descptr,
                        &sigdata);
    }
}
